Via language hat:

There are three good reasons for studying metre. First and most important, the study of metre increases our appreciation of the poem as a work of art; without it, we cannot read a poem adequately, even to ourselves, and all its musical qualities will be lost to us. Secondly, and understanding of the subtleties of metre adds to our aesthetic pleasure an intellectual pleasure; the skill of a great poet in handling a difficult and complicated metre can be an object of admiration in itself. Thirdly, a knowledge of metre is of the greatest use in textual criticism; the fact that a line has been corrupted in transmission may be revealed by a defect in scansion which in itself may be an invaluable guide to the true reading.